Examples for 8th grade - page 83

1. Four integers
Fnd four consecutive integers so that the product of the first two is 70 times smaller than the product of the next two.
2. Internal angles
Find the internal angles of the triangle ABC if the angle at the vertex C is twice the angle at the B and the angle at the vertex B is 4 degrees smaller than the angle at the vertex A.
3. Sales off
Goods is worth € 70 and the price of goods fell two weeks in a row by 10%. How many % decreased overall?
4. Liters od milk
The cylinder-shaped container contains 80 liters of milk. Milk level is 45 cm. How much milk will in the container, if level raise to height 72 cm?
5. Gloves
I have a box with two hundred pieces of gloves in total, split into ten parcels of twenty pieces, and I sell three parcels. What percent of the total amount I sold?
6. Repair company
The company repairs cars. The first day repair half of the contract second day, the half of the rest and third day 8 residue cars. How many total cars company repaired?
7. Fit ball
What is the size of the surface of Gymball (FIT - ball) with a diameter of 65 cm?
8. The plan
Students have collected 48 kg of paper which is 16% of the plan. How many kg of paper still have to collect to fulfill the plan?
9. Circular ring
Square with area 16 centimeters square are inscribed circle k1 and described circle k2. Calculate the area of circular ring, which circles k1, k2 form.
10. Metal pyramid
Find the weight of a regular quadrilateral pyramid with a 5 cm length and 6,5 cm body height is made from material with density g/cm3.
11. The swing
To swing the two girls. Aneta weight 45 kg and Simon 35 kg weight. How far should sit Simon from the middle of swing so it is balanced, if we know that Aneta is sitting at distance 1,5m? How far are girls sitting apart?
12. Fertilizer
Meadow with an area of 1,500 square meters was fertilized with 12 kg of urea. Urea contains 45% nitrogen. How much nitrogen accounted per 1 m2?
13. Equilateral triangle
The equilateral triangle has a 23 cm long side. Calculate its content area.
14. Square
Danov's father has a square of 65.25 milligram square of wire with a diagonal. How will the square be big when one mm weighs 7 mg?
15. Gardens
I have a garden in the shape of a square with a side length of 0.02 kilometers. Neighbor has a large garden as well and one side of the garden we share. I'd bought from a neighbor garden that my area of my garden increased to 5 ares. a/ By how many acres I
16. Weights
Marry and John together weighing 49 kg. Their weights are in ratio 1:6. Determine their weights.
17. Runner 2
Marian run 12 meters in 8 seconds. How far would Marian run for 70 seconds, if still run at the same pace?
18. Cylinder
In a 1-meter diameter cylinder is 1413 liters of water, which is 60% of the cylinder. Calculate the cylinder height in meters, do not write the units. The resulting value round and write as an integer.
19. Friends
James and Jaroslav are friends. Together they had 48 toy cars. But if John took 8 cars from Jaroslav, Jaroslav will be have 1.5 times more toy cars than James. How many toy cars had Jaroslav and James?
20. Class
In a class are 32 pupils. Of these are 8 boys. What percentage of girls are in the class?

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